1. Field of the Invention
The present invention relates generally to a cannula used as an aid for insertion of catheters and other instruments into the body of a patient and more particularly to a grooved balloon catheter director apparatus used in surgical procedures such as Carpal Tunnel Syndrome.
2. Brief Description of the Background
It is a frequent practice when introducing balloon catheters and other catheters or instruments into the body to first introduce a cannula or sheath to aid in the introduction of the catheter or other instruments. The present invention is directed to the use of a grooved catheter director apparatus used in surgical procedures such as Carpal Tunnel Syndrome which increases the spatial diameter of the carpal tunnel enclosing the nerve.
Historically, carpal tunnel syndrome has been treated nonsurgically by splinting of the affected hand and wrist, oral anti-inflammatory medication, and local steroid injection. If nonsurgical methods are unsuccessful, surgical intervention is required.
Open surgical decompression of the carpal tunnel by division of the transverse carpal ligament was first described in 1930 by Learmonth. Open procedures generally entail a curved longitudinal incision parallel to the thenar crease. Taleisnik has described an incision along the ulnar border of the ring finger axis (Taleisnik, J.: The palmar cutaneous branch of the median nerve and the approach to the carpal tunnel: An anatomical study; J. Bone Joint Surg, 55A: 1212, 1973). This incision may be extended proximally to the wrist flexor crease. Angling the incision towards the ulnar aspect of the wrist helps to avoid cutting the palmar sensory cutaneous branch of the median nerve. This nerve is located in the interval between the palmaris longus and the flexor carpi radialis tendons. After division of the skin and subcutaneous tissue, the transverse carpal ligament is identified and divided along its ulnar border to avoid and to prevent injury to the median nerve or its recurrent branch. It is to this application that the present grooved director device has been developed.
Various patents disclose devices for inserting or placing catheters within chosen parts of the human body. U.S. Pat. No. 4,655,214 discloses a soft inflatable sheath having a closed rounded distal tip that is inserted through a catheter and inflated adjacent the distal tip of the catheter prior to intubation. The proximal end of the sheath is sealed to maintain it in expanded inflatable condition when the catheter is being intubated. Following intubation the cylindrical sheath is deflated and withdrawn. U.S. Pat. No. 4,645,491 discloses a catheter placement apparatus used in inserting a catheter to a preferred depth. The device comprises a surgical needle provided with a thin-walled transparent polytetrafluoroethylene tube which is heat shrunk over the stem portion of the needle to form a longitudinal window allowing a catheter inserted in the needle to be viewed. The catheter has a colored patch of the same length as the window and a series of spaced circular bands of differing colors allowing the position of the catheter to be accurately located by lining the colored patch with the window and advancing the catheter until at least one band appears in the window. The color and distance of the band nearest to the surface of the patient's skin are used to determine the position of the catheter. The needle is withdrawn by sliding it along and off the catheter. U.S. Pat. No. 2,164,926 discloses a catheter stylet with an eye or aperture positioned on an opposite lateral wall behind the tip. U.S. Pat. No. 3,537,452 discloses a needle guard and beveled cutter for use with intravenous catheterization units. The device has a tubular body with a flat base and a longitudinally slotted top. The diameter of the tube is greater than the diameter of the needle contained therein. U.S. Pat. No. 3,592,193 discloses a removable needle guide to be used with a flexible catheter tube in withdrawing or introducing fluids relative to a body. The hollow tubular needle guide has a sharpened needle portion provided at its proximal end for puncturing the skin, tissues and veins of the body where the needle is inserted. At its distal end, winged handles are associated therewith which provide controlled insertion and removal from the body with subsequent attachment from a flexible catheter tube. U.S. Pat. No. 5,011,478 discloses an introducer set including a sheath and dilator formed with a smooth external shape. The distal end of the sheath is embedded in the dilator and formed in angle oblique to the longitudinal access of the introducer set. U.S. Pat. No. 3,559,643 discloses a catheter placement unit for insertion of a catheter into a body lumen through an incised opening in the lumen wall. The unit includes a longitudinally slit sheath having a catheter therein and an advancer connected to one end of the catheter, initially in axial alignment with the sheath to close the end of the sheath.
None of the aforenoted prior art has provided a solution to problems found in carpal tunnel surgery.